Minimally invasive endoscopic surgery is performed using two or more trocar sheaths for gaining access to a cavity of a patient. These trocar sheaths provide access to the surgical site for various medical instruments such as forceps, scissors, and scopes. The advantages of endoscopic surgery over traditional, open surgery include decreased trauma for the patient, smaller wounds and less scarring, faster healing and recovery time, and decreased risk of infection.
A problem presented by endoscopic surgical procedures is that a surgeon has no direct visualization of the surgical site. Instead, visualization of the surgical site is by a video camera and monitor. The surgeon uses medical devices inserted through access sheaths to manipulate tissue adjacent the surgical site for lifting tissue out of the line of sight. A solution to this problem is the use of an additional access sheath for inserting forceps or a grasper to the surgical site for retracting tissue. A limitation of using these sheaths, however, is that the trocar sheaths normally range in size from 3 to 10 mm and leave deep, cylindrical wounds where a significant bulk of tissue is removed. As a result, surgeons tend to use as few access sheaths as possible.
In endoscopic surgical procedures, the surgeon does not directly manipulate tissue as in traditional, open surgery. To perform the task of moving tissue aside and away from the surgical site, the surgeon or surgical assistants must insert forceps or a grasper through an access sheath, grasp the desired tissue, move the tissue aside, and then manually maintain the position of the grasper and tissue for the duration of a surgical procedure. A problem with manually stabilizing medical devices such as a grasper is that the surgeon or surgical assistants lack control over the grasper and tissue due to muscle fatigue or inadvertent movement over the duration of the procedure. Another problem with the use of these known medical devices for repositioning tissue is that one or both hands of each surgeon or surgical assistant are occupied. When the surgeon or surgical assistant must release a device prematurely to perform a more urgent task, as often happens during surgery, the tissue returns to its original position. As a result, the surgeon's line of sight or access to the surgical site is obstructed, and operative time is extended.